la_pipes is for automating la_eu projects

Meant to reduce efforts and increase reusability we centralize pipelines.
Currently we have a own pipeline definition file per project to include.
Instead of putting .gitlab-ci.yml into every repo we just reference them:

https://git.drupalcode.org/project/$PROJECT/-/settings/ci_cd#js-general-pipeline-settings

CI/CD configuration file: la_fr.gitlab-ci.yml@project/la_pipes:main

Create SSH key for GitLab repo automation

Create a ED25519 type SSH key pair with $PROJECT@drupalcode.org:

$ ssh-keygen -t ed25519 -C la_fr@drupalcode.org -f id_la_fr
Generating public/private ed25519 key pair.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in id_la_fr
Your public key has been saved in id_la_fr.pub
The key fingerprint is:
SHA256:S59FHlaW5kqIQ31vwVd5HgN6En7fbsRB8wN62O35GLM la_fr@drupalcode.org
The key's randomart image is:
+--[ED25519 256]--+
|         . . ++++|
|        . o BoO+=|
|       . . O+O B=|
|        o .+*.*.*|
|        S. .ooo++|
|       . o o.  B.|
|        . o   E +|
|               . |
|                 |
+----[SHA256]-----+

Convert the private key to BASE64 and to store as GitLab variable:

$ cat id_la_fr | base64 | tr -d '\n'

Add CI/CD variable on the project and with the key SSH_PRIVATE_KEY_BASE64:

https://git.drupalcode.org/project/$PROJECT/-/settings/ci_cd#js-cicd-variables-settings

Select option Masked and Hidden and deselect Expand variable reference:

Add the public key as deploy key in the repository settings under Deploy keys:

https://git.drupalcode.org/project/$PROJECT/-/settings/repository#js-deploy-keys-settings

Select Grant write permissions to this key to grant the GitLab CI write access.

Add public key via la_eu maintainer

To enable the upstream automation the public key needs access to la_eu.
If you're not an la_eu maintainer ask one to add it writeable here:

https://git.drupalcode.org/project/la_eu/-/settings/repository#js-deploy-keys-settings

We need to inially create the branch downstream/$PROJECT in the la_eu repo. Also in the downstream repo ensure Git shallow clone option is deactivated by 0

https://git.drupalcode.org/project/$PROJECT/-/settings/ci_cd#js-general-pipeline-settings